Aromatic and heterocyclic esters of the non-quaternary carbon-4-piperidinol system exhibited analgesic activity in mice, no physical dependence liability of the morphine-type in monkeys and rats and little or no binding to the opiate receptor. A 3-substituted piperidine of this series showed narcotic antagonist properties similar to that displayed by Cyclazocine. Piperidinol esters, dissimilar to those displaying good analgesic activity, were active in the maximal electroshock antiepileptic assay in mice. Pyrrole-carboxylic acids showed good activity in antiinflammatory and antiproteolytic assays. Certain substrates within these three disciplines are being studied for their respective receptor interaction.